Spark-plug.



W. M. SLBAPORD.

Patented Aug.A 24, `1909.

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:part oi the plug.

a cleaning member.

.grounded connection.

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serian-PLUG.

Application filed November 16, 1907.l Serial No. 402,413.

To all 'wiz/om 'it may concern; secured in any suitable manner on the lower Be it known that' I, WlLLrAM M. SLEA- end of the stem beyond the bushing, as beronn, a citizen of the United States ci Amertween an outer bur 12 and innerl nut 13 ica, residing at Brighton, in the county of screw-threaded on the stem, Livingston and State of Michigan, have invented certain 'new land useful improvements in Sparlr-Plugs,'of which the iol owing is a specific-ation,reference being had therein to the accompanying drawings.

During the use of spark plugs oi' lthe jump-spark type in interna combustion motors, *.l-.e terminals become more or less coated with the products of combustion, and l thereby become short circuited or the elliciency is impaired in other ways.

This invention relates to a spark plug of the jump spark ty )e provided with means whereby the terminals may be mechanically l bushing. .The up er face 14 of the cleaner spondingly fitted annular face 15 of the bushing, against which. it is normally held by a spring part of the stem 10 in compression between a stem and the bushing, a and washer 19 affordir means for a wireconner free rotation of the stem.

xl, and allowing cleaned at any moment at will of the operator, Without removing or disturbing the plug. The invention consists in the matters hereina'l'ter set forth, and more particularly pointed out in the appended claims.

Referring to the drawings, VFigure 1 is a view partially in elevation and partially in section, oi' a spark plug embodying features of the invention, with the terminals in normal l Fig. 2 is a similar view with the parts in position 'lor cleaning. Fig. 3 is a view in detail ol`- a central movable electrode. Fig. 4 is a View in end elevation oi the lower Fig. 5 is a view in detail oi Fig. 6 is a view in section ol line x-a ci' F ig. l.

ln the drawings, l indicates an outer metal sleeve tapered, screw-threaded and Ylit-ted for insertion in the customary manner in an en.u gine cylinder, wh ere it forms the usual A bridge 2 depends from the lower end oi' 4the sleeve, with which it is preferably integral,and has upper convergent arms B with concave inner 'laces 4 which present sharp edges 5. A terminal il upper part of the cleaner with reasonably sharp corners are adapted to sweep the inner fr :e of the sleeve 1, and the conical p e pitch to the inner faces 4 ofthe obli ue arms of the bridge, so that it contacts lt ierewith when the stem is projected. A lowercylindrical part or nipple 23 of the' cleaner with slightly roughened, corrugated or fiuted periphery, is likewise adapted. to scrape the end of the terminal 6 when the cleaner bears against the arms.

A cylindrical axial terminal stud 24 of suitable material is secured in the end of' the stem 10 so that it is separated by a pro er spark interval from the other termina 6 when the stem is in normal position. A 25 inthe bridge 2 allows the l circular aperture terminal to pass through when the stem is l minal so as to contact therewith at one point ol its eriphery. The aperture is inwardly tapere so as to form a sharp edge 26 which scrapes the" terminal when the latter is pushed through. A nut 27 of insulating of suitable metal is screwethreadcd in or material and ap otherwise suitably secured in a lower leg 7 of l means for manipu ating the stern. the bridge so as to projectradially inward, a In operation, by pushing the stem down check-nut S liolding'it in adjusted/position, l and turning it as or it may be permanently set, if desired. sweeps olif any deposit inside the sleeve, and A bushing Q of. insulating material, prel'eifrom the end of the stationary terminal, and ably porcelain, is secured concentrically in its conoidal tace is in turn scraped oil' by the the usual manner in the sleeve, and a rotataedges of the oblique arms of` the bridge. At ble metal stem 10 is longitudinally reci rocathe same time the terminal stud on the stem ble in the axial aperture. A conical c eaner is being cleaned Iby the sharp (',orner of the 1i of porcelain or like insulating material is bridge aperture.

Specification o Letters Patent. Patented Aug. 24:, 1909.

form a guide sliding 1n the lower end of the 16 encircling the upper projecting' Two or more projections or spurs 21 on thev the latter nut.- i' being preferably elongated and cylindrical to is ground to seatitself tightly on the-correhead or cap-nut 17 on the outer end of the hollow ferrule 18 "table retaining riphery 22 of the cleaner corresponds. in

projected and is slightly eccentric to the terl ropriate design aiiords roo it 1s advanced, the cleaner'.

' vbrought into rubbing contact wit the spirit of the invention and l d o not care to limit myself to any particular form or arran ement of parts.

at I claim as my invention is 1". In a spark plug, a fixed terminal on the inner end thereof, and a movable terminal l sleeve, an msulating bushmg secured thereprovided with a cleaning member adapted to be brought into rubbing contact with the fixed terminal and an 'ad'acent interior surface formed on the plug, y manipulation of said terminal.

2. In a spark plug, a fixed terminal on the inner end thereof, a terminal longitudinally and rotatably movable inthe plug, a cleaning member ada ted to be brought into rubbing contact wit the fixed terminal and ad- 'acentinterior surfaces formed on the plug,

y manipulation of the movable terminal, and means for manipulating the movable terminal. l

y3. A spark plug comprising an outer metalsleeve, a terminal secured to the inner end thereof, an insulating bushing in the sleeve, astem longitudinally movable in the bushing having a terminal on its inner end and a cleaner on the stem adapted to be n the 'lixed terminal andthe adjacent inner face of the sleeve .by the movement of the stem.

v 4. A* spark plug comprising an outer metal sleeve, a terminal secured to the inner end thereof, ani'w insulating bushing in; the sleeve, a stem longitudinally movable in the bushing having a terminal on its Aend adjacent the fixed terminal, -a spring adapted' to hold the stem normally retracted with the terminal in operative relation to the fixed terminal, and a cleaneron. the stem adapted to be broughtinto rubbing Contact with. the ixed terminal and the adjacent inne1 surfaces 'oftlievsleve when the stem is moved from its retracted position.

, 5f In la spark plug, an outer metallic sleeve,` an vinsulating bushing secured thereon, a bridge spannin the lower end of the sleeve, a terminal in t 1e bridge extcndingrw dially inward, a rotatable stein lengitudin ally movable i'n the bushing having an axial terminal on its end adjacent the bridre terminal, and a cleaning member on t ie stein adapted vto be brought into rub )ing engagement with. the bridge and its terminal when the stem is moved. p, 6. In a spark plug, an outer metallic `member of porcelain on the Vstem having s urs adapted to sweep the inner facey of the s eeve below the bushing, a peri hery coned to contact with the arms, and a uted 'nipple adaptedtoy scrape the end of the bridge terminal when the stem is rotatively projected toward the bridge, and a springadapted to hold the stem normally retracted w1th the terminals in operative relation.

7. In a spark plug, an outer lmetallic in, a bridge secured by convergent upper arms to the lower end of the sleeve, a terminal in the bridge extending radially inward, a rotatable stem longitudinally movable in the bushing having an axial terminal on its end adjacent the bridge terminal, a chaining member of porcelain on the stem having s urs adapted to sweep the inner face of the s eeve below the bushing, a 'peri )hery coned to contact with the arms, and a ilutedl'nipple adapted to scrape the end ofthe bridgeterminal when the stem is rotatively projected toward the bridge, and a spring adapted to hold the stem normally retracted with thc terminals in operative relation, said arms having concave inner faces corresponding to the cleaner edges.

S. In a spark plug, an outer metallic sleeve, an insulating bushing secured therein, a bridge spanning the lower end el" thc sleeve, a terminal in the bridge extending radially inward, a rotatable stem longitudinally movable in the bushing having an axial terminal on its end adjacent the bridge terminal and a cleaning member on thc stein adapted to bc brought into rubbing engagement with the bridge and its termina-l when the stein is 1noved,the bridge having a circular aperture slightly eccentric to the axis of the stem terminal with a beveled margin adapted to con-4 tact with and. to scrape the periphery of the periphery-"and sharp lateral innerk stein terminal when tlie llatter is projected.

through the brid e b the stem movement.

9. lh a spar p ug, an outerv metallic sleeve, an insulating bushing secured therein, a bridge spanninf-r the lower end of the sleeve, a terminal in t 1e bridge extending radially inward, a rotatable stern longitudinally movable in the bushing having an axial terr minal on its end adjacent the-bridge termi--v nal, a cleaning member of porcelain. onl the stem having spurs ada ted to sweep the inner face of the sleeve iielow the bushing, a peripheryconed to contact with the arms, and a luted nipple adapted to scrape the ond ofthe bridge terminal when the stem is rota- WILLIAM M. SLEAFGRI).

Witnesses C. R. STUKNEY, OTTO F. BARTHEL.

tively projected toward the bridge, the inner annular face of the cleaner being adapted to seat itself on the lower end of the bushing and form a tight joint therewith when the 5 stem is retracted, and e, spring adapted to hold-tl1e stem normally retracted with the terminals in operative relation. 

